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Joined: Apr 2017
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Talk Morgan Enthusiast
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Talk Morgan Enthusiast
Joined: Apr 2017
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New Ford Transit MT-75 gearbox speedo sensor £199. Conversion to the hub mounted system <£60. Can't see why it wouldn't work as the VDO speedo accepts a Hall Effect Input and can be calibrated to suit the correct number of pulses from the hub bolts. (5 bolt on the 4/4) Any thoughts on why it might not work. I'm starting to understand the charm of owning and working on a Morgan.
Bob
2009 Black Roadster 1999 4/4 2 litre Zetec
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Roadster Guru Member of the Inner Circle
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All I would say is that Morgan add five extra bolts to the offside hub. If they could have used just five I suspect they would have done, so five may not be enough for a low speed sensing.
DaveW '05 Red Roadster S1 '16 Yellow (Not the only) Narrow AR GDI Plus 4
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Talk Morgan Enthusiast
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Talk Morgan Enthusiast
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Posts: 1,799 Likes: 4 |
So you only have 10 bolts on the offside hub? I could easily get my friendly machine shop to add the extra bolts but it will be interesting to try the 5 first and test your theory. The VDO info suggests it will work but you could well be right or why else would MMC add extra bolts to the one side only. I thought you had 10 because it was a Roadster.
Bob
2009 Black Roadster 1999 4/4 2 litre Zetec
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Look at the first image as you scroll up from here Bob. That's the 2012 Plus 4 hub with ten bolts.
DaveW '05 Red Roadster S1 '16 Yellow (Not the only) Narrow AR GDI Plus 4
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Joined: Apr 2017
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Talk Morgan Enthusiast
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Talk Morgan Enthusiast
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Ahah, I thought that was your Roadster hub. I'll try 5 bolts first then add 5 if I need to. Thanks for your help and for all the brilliant "how to" posts you do. They have been a great help and inspiration to a new owner like me!
Bob
2009 Black Roadster 1999 4/4 2 litre Zetec
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Joined: Dec 2008
Posts: 22,357 Likes: 353
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Thanks Bob. 
DaveW '05 Red Roadster S1 '16 Yellow (Not the only) Narrow AR GDI Plus 4
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Formerly known as Aldermog Member of the Inner Circle
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Formerly known as Aldermog Member of the Inner Circle
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All the Trads Bob. Don't know about the Aeros. Dave, do they use the wheel mounted sensor so that it reads correctly, irrespective of the wheel/tyre size used? If the sensor is on the transmission it would have to be calibrated each time the wheel/tyre size changed. I think that on the Aeros the speedo is driven using data from the ABS sensors, but I could be wrong.
Peter, 66, 2016 Porsche Boxster S No longer driving Tarka, the 2014 Plus 8...
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Salty Sea Dog Member of the Inner Circle
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Salty Sea Dog Member of the Inner Circle
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The same would apply to wheel sensors Peter - a change of diameter / circumference will give different number of rotations over distance.
Graham (G4FUJ)
Sold L44FOR 4/4 Giallo Fly '11 MINI Countryman Cooper D All4 '90 LR 90 SW
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The calibration must be at the speedo I suppose. There's nothing at the wheel end.
DaveW '05 Red Roadster S1 '16 Yellow (Not the only) Narrow AR GDI Plus 4
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Talk Morgan Enthusiast
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Talk Morgan Enthusiast
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Correct, the calibration is at the speedo. The VDO speedo has a choice of inputing the pulses per mile or by a procedure involving driving an exact mile. I'm no longer driving the speedo via the ECU as I've stripped out the Ford ECU and installed an OMEX 600 as a precursor to doing some engine tuning work. I've already installed the Librands Manifold then re-mapped on the Dyno to get 127 HP instead of the standard Ford 115 HP. So now my Speedo will drive directly from the Hall Effect Sensor on the hub. My rough calc is about 4100 pulses per mile with the 5 bolt hub but I haven't double checked that yet. When I've got the rough calibration correct I'll do a more accurate GPS distance and speed check. At some point I will probably change to 175/70R15 tyres so I can re-calibrate it again then.
Bob
2009 Black Roadster 1999 4/4 2 litre Zetec
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